<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>
<script>
    function parseQueryString(str){
        let json1={}
        let arr=str.split("&")
        for(let i=0;i<arr.length;i++){
            let str=arr[i].split("=");
            json1[str[0]]=str[1];
        }
        return json1
    }
    let str="admin=user&pass=1234";
    console.log(parseQueryString(str));
</script>